September 6, 2013
Many patients enter the test booth of an audiology center convinced of a decrease in their ability to hear. The most common reason given is difficulty following conversation, perhaps most markedly in subpar acoustic environments. Often spouses or family members make note of changes over time. They may even report an increase in TV volume. What are we to decide when the hearing evaluation reveals normal middle ear function and no change in actual hearing levels?
Research on the brain and hearing system has demonstrated the possibility of disruptions in listening capability NOT directly related to hearing levels. We have stated in earlier blog entries the complexity of the hearing system, from the outer ear to the cortex of the brain. This system depends on the “transduction” of acoustic sound energy to mechanical vibrations to nerve impulse patterns involving multiple structures and a pathway routing information, often in both directions. Any malfunction or interruption of the speed of transmission of all this information may interfere with what we call AUDITORY PROCESSING.
Auditory processing refers to the coordination within the hearing system that accurately transports auditory signals towards the brain and extracts meaning from the information. Processing disorders can interfere with timing of the signals reaching the brain, the ability to utilize both ears effectively, the ability to understand a message with missing information (such as in poor acoustic environments), and other necessary elements of good hearing.
Strategies of habilitation for impaired auditory processing may differ from those found to be effective for common hearing loss. Identification is the first step. Let us evaluate your ears and determine the best path to take to maximize hearing, communication and quality of life.